Control method for fuel cell power

ABSTRACT

A power controlling method for a power supplying system coupled to a load is disclosed. City energy is detected. It is determined whether the city energy corresponds to a first pre-determined condition. When the city energy corresponds to the first pre-determined condition, the city energy is transformed to generate a main power to the load. When the city energy does not correspond to the first pre-determined condition, a fuel cell unit is activated to provide a backup power to the load.

CROSS REFERENCE TO RELATED APPLICATIONS

This Application claims priority of China Patent Application No.201210138991.0, filed on May 7, 2012, the entirety of which isincorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a power control method, and more particularlyto a power control method, which provides power when city energy isunstable.

2. Description of the Related Art

When a conventional power supply system drives a load, the conventionalpower supply system transforms city energy to power required by theload. However, the conventional power supply system cannot normallydrive the load when the city energy is unstable, such as power trip orpower failure. Thus, the load cannot normally operate. If the load is animportant device, such as a base station or a fileserver, it isinconvenient to transmit information when the load cannot normallyoperate.

BRIEF SUMMARY OF THE INVENTION

A power controlling method for a power supplying system coupled to aload is provided. An exemplary embodiment of a power controlling methodfor a power supplying system is described in the following. A cityenergy is detected. It is determined whether the city energy correspondsto a first pre-determined condition. The city energy is transformed togenerate a main power to the load when the city energy corresponds tothe first pre-determined condition. A fuel cell unit is activated toprovide a backup power to the load when the city energy does notcorrespond to the first pre-determined condition.

A detailed description is given in the following embodiments withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be more fully understood by referring to the followingdetailed description and examples with references made to theaccompanying drawings, wherein:

FIG. 1 is a schematic diagram of an exemplary embodiment of a powercontrolling method;

FIG. 2A is a schematic diagram of an exemplary embodiment of a powersupplying system;

FIG. 2B is a schematic diagram of an exemplary embodiment of a port ofthe power supplying system shown in FIG. 2A;

FIG. 3 is a schematic diagram of an exemplary embodiment of arecombination confirmed action;

FIG. 4 is a schematic diagram of an exemplary embodiment of a standbymode;

FIG. 5 is a schematic diagram of an exemplary embodiment of apre-turning on mode;

FIG. 6A˜6B are schematic diagrams of an exemplary embodiment of aturning on mode;

FIG. 7A˜7B are schematic diagrams of an exemplary embodiment of theoperation mode;

FIG. 7C is a schematic diagram of an exemplary embodiment of controllingeach supply device; and

FIG. 8A˜8B are schematic diagrams of an exemplary embodiment of aturning off mode.

DETAILED DESCRIPTION OF THE INVENTION

The following description is of the best-contemplated mode of carryingout the invention. This description is made for the purpose ofillustrating the general principles of the invention and should not betaken in a limiting sense. The scope of the invention is best determinedby reference to the appended claims.

FIG. 1 is a schematic diagram of an exemplary embodiment of a powercontrolling method. The power controlling method is applied to a powersupplying system. In this embodiment, the power supplying system drivesa load according to city energy.

First, the city energy is detected (step S110) and then it is determinedwhether the city energy corresponds to a first pre-determined condition(step S120). When the city energy corresponds to the firstpre-determined condition, it represents that the city energy is stable.Thus, the city energy is transformed to generate a main power to theload (step S130). However, when the city energy does not correspond tothe first pre-determined condition, it represents that the city energyis unstable. Thus, a backup power is provided to the load (step S140).

In this embodiment, a fuel cell unit is utilized to generate the backuppower. The invention does not limit the types of the main power and thebackup power. In one embodiment, each of the main power and the backuppower is an AC type or a DC type.

FIG. 2A is a schematic diagram of an exemplary embodiment of a powersupplying system. The power supplying system 200 provides power to theload 210 and comprises a transformation unit 220, a recombination unit230, a fuel cell unit 240, a power transformation unit 250 and acontrolling unit 260.

The transformation unit 220 generates the main power V_(MA) to drive theload 210 according to the city energy V_(AC). The invention does notlimit the circuit structure. Any circuit structure can serve as thetransformation unit 220, as long as the circuit structure is capable ofgenerating power according to the city energy. In one embodiment, thetransformation unit 220 is a transformer.

The recombination unit 230 recombines a methanol component C_(HY) togenerate a hydrogen component C_(MA). The fuel cell unit 240 generates apower V_(FC) according to the hydrogen component C_(MA), a watercomponent C_(W) and an air component C_(A). The power transformationunit 250 transforms the power V_(FC) to generate a backup power V_(SUB)to the load 210. The controlling unit 260 controls operations of therecombination unit 230, the fuel cell unit 240 and the powertransformation unit 250 to immediately provide the backup power V_(SUB)to the load 210 when the city energy V_(AC) is unstable.

In this embodiment, the power supplying system 200 further comprises aremote unit 270 and a patrol detection unit 280. The controlling unit260 transmits operation status of each unit to a remote terminal via theremote unit 270. Thus, a remote user is capable of monitoring theoperation status of the power supplying system 200.

Additionally, the patrol detection unit 280 detects the voltage of eachfuel cell of the fuel cell unit 240. The controlling unit 260 adjustsand controls each unit (e.g. 230, 240 and 250) according to thedetection result generated by the patrol detection unit 280.

FIG. 2B is a schematic diagram of an exemplary embodiment of a port ofthe power supplying system shown in FIG. 2A. The recombination unit 230comprises a temperature control device 241, an oxidization protectiondevice 232, a concentration protection device 233, a reformer 234 and anoperation detection device 235, but the disclosure is not limitedthereto. Any circuit can serve as the recombination unit 230, as long asthe circuit is capable of recombining the methanol to generate thehydrogen and executing control of the recombination action

The temperature control device 231 controls the internal temperature ofthe recombination unit 231. The oxidization protection device 232 avoidsthe situation where the reformer 234 is oxidized. The concentrationprotection device 233 avoids the situation where the internal hydrogenconcentration of the recombination unit 230 is too high. The reformer234 recombines the methanol component C_(HY) and generates the hydrogencomponent C_(MA). The operation detection device 235 detects theoperation statuses of the temperature control device 231, theoxidization protection device 232, the concentration protection device233 and the reformer 234 and notifies the controlling unit 260 of thedetection results. In this embodiment, the temperature control device231, the oxidization protection device 232, the concentration protectiondevice 233 and the operation detection device 235 make the reformer 234operate at an optimum status.

The fuel cell unit 240 comprises a cooling water supply device 241, ahydrogen supply device 242, an air supply device 243, a cooling waterdetector 244, a hydrogen detector 245, an air detector 246, a hydrogenconcentration protection device 247, a temperature control device 248and a cell stack 249, but the disclosure is not limited thereto. Anycircuit structure can serve as the fuel cell unit 240, as long as thecircuit structure is capable of generating power according to a hydrogencomponent, a water component and an air component.

In this embodiment, the cooling water supply device 241 provides coolingwater to the cell stack 249. The hydrogen supply device 242 provideshydrogen to the cell stack 249. The air supply device 243 provides airto the cell stack 249. The cell stack 249 generates the power V_(FC)according to the cooling water, the hydrogen and the air. In thisembodiment, the cooling water and the air come from external and thehydrogen is provided by the recombination unit 230.

The cooling water detector 244 detects the providing status of thecooling water supply device 241 and notifies the controlling unit 260 ofthe detection result. The hydrogen detector 245 detects the providingstatus of the hydrogen supply device 242 and notifies the controllingunit 260 of the detection result. The air detector 246 detects theproviding status of the air supply device 243 and notifies thecontrolling unit 260 of the detection result. The hydrogen concentrationprotection device 247 avoids the situation where the internal hydrogenconcentration of the fuel cell unit 240 is too high. The temperaturecontrol device 248 controls the internal temperature of the fuel cellunit 240.

In one embodiment, the fuel cell unit 240 comprises a plurality ofdetection devices (not shown) to detect the status (e.g. a temperaturestatus, a pressure status and a liquid status) of the fuel cell unit240. The controlling unit 260 controls the hydrogen concentration device247 and the temperature control device 248 according to the detectionresults generated by the detection devices. In other embodiments, thehydrogen concentration device 247 and the temperature control device 248controls the hydrogen concentration and the temperature of the fuel cellunit 240 according to the detection results generated by the detectiondevices.

The power transformation unit 250 comprises a transformation adjustmentdevice 251, a storage device 252, a city energy detector 253, aprotection device 254 and a voltage current detector 255, but thedisclosure is not limited thereto. In another embodiment, any circuitstructure can serve as the power transformation unit 250, as long as thecircuit structure is capable of transforming power.

The transformation adjustment device 251 transforms the power V_(FC) andgenerates the backup power V_(FC) according to the transformed result.The storage device 252 stores power. The city energy detector 253determines whether the city energy V_(AC) is stable. The protectiondevice 254 protects the cell stack 249. The voltage current detector 255detects the power V_(FC) and provides the detection result to thecontrolling unit 260.

The controlling unit 260 comprises a receiving element 261, a commandelement 262 and an operation element 263, but the disclosure is notlimited thereto. In other embodiments, any circuit structure can serveas the controlling unit 260, as long as the circuit structure is capableof generating a corresponding control signal according to the detectionresults generated by the detectors.

The receiving element 261 receives the detection results generated bythe detectors in the recombination unit 230, the fuel cell unit 240 andthe power transformation unit 250 and transforms each detection resultinto an appropriate value according to the specification of eachdetector. The operation element 263 executes a determining action and anoperation according to the transformation results generated by thereceiving element 261. The command element 262 controls thecorresponding unit to activate, de-activate or adjust the operation ofeach element according to the determining result.

When the power supplying system operates in a standby mode, apre-turning on mode and an operation mode, a recombination confirmedaction is executed to confirm that the recombination unit 230 is normal.FIG. 3 is a schematic diagram of an exemplary embodiment of arecombination confirmed action. First, it is determined whether areformer of the power supplying system has been activated (step S310).When the reformer has been activated, it is determined whether anoperation status of the reformer corresponds to a second pre-determinedcondition (step S350). In one embodiment, in step S350 is to determineat least one of the temperature of the reformer, an amount of a methanolcomponent disposed in a methanol tub of the reformer and an amount of ahydrogen component disposed in a hydrogen storage device of thereformer.

For example, when the temperature of the reformer corresponds to arecombination pre-determined temperature, the amount of the methanolcomponent disposed in the methanol tub corresponds to a pre-determinedmethanol amount and the amount of the hydrogen component disposed in thehydrogen storage device corresponds to a pre-determined hydrogen amount,it represents that the operation status of the reformer corresponds tothe second pre-determined condition. Alternatively, when at least one ofthe temperature of the reformer does not correspond to the recombinationpre-determined temperature, the amount of the methanol componentdisposed in the methanol tub does not correspond to the pre-determinedmethanol amount and the amount of the hydrogen component disposed in thehydrogen storage device does not correspond to the pre-determinedhydrogen amount, it represents that the operation status of the reformerdoes not correspond to the second pre-determined condition.

When the operation status does not correspond to the secondpre-determined condition, error information is sent (step S331) and thereformer is de-activated (step S332). In one embodiment, the errorinformation is transmitted to a remote terminal via the remote unit ordisplayed in a monitor. In other embodiments, step S331 can be omitted.

When the operation status corresponds to the second pre-determinedcondition, it is determined whether the reformer corresponds to aturning off condition (step S360). In one embodiment, in step S360 is todetermine whether the amount of the hydrogen component disposed in thehydrogen storage device of the reformer corresponds to a hydrogencondition. In one embodiment, the hydrogen condition is a maximumhydrogen storage amount of the hydrogen storage device. When the amountof the hydrogen component disposed in the hydrogen storage device of thereformer corresponds to the hydrogen condition, it represents that thereformer corresponds to the turning off condition. Thus, the reformer isde-activated (step S370).

When the amount of the hydrogen component disposed in the hydrogenstorage device of the reformer does not correspond to the hydrogencondition, it represents that the reformer does not correspond to theturning off condition, thus, the original step of the corresponding modeis executed. For example, if the recombination confirmed action isexecuted in a standby mode, when the reformer does not correspond to theturning off condition, the original step (S410) of the standby mode isexecuted. The operations of the power supplying system in the differentmodes are described in more detail below.

When the reformer does not be activated, it is determined whether thereformer needs to be activated (step S320). In one embodiment, in stepS320 is to determine whether the amount of the hydrogen componentdisposed in the hydrogen storage device of the reformer corresponds tothe hydrogen condition. When the amount of the hydrogen componentdisposed in the hydrogen storage device of the reformer corresponds tothe hydrogen condition, it represents that the reformer does not need tobe activated. When the amount of the hydrogen component disposed in thehydrogen storage device of the reformer does not correspond to thehydrogen condition, it represents that the reformer needs to beactivated.

When the reformer does not need to be activated, the temperature of thereformer is controlled (step S321) and the situation is avoided wherethe reformer is oxidized (step S322). When the reformer needs to beactivated, it is determined whether the operation status of the reformercorresponds to the second pre-determined condition (step S330). In thisembodiment, the determining method of step S330 is the same as thedetermining method of step S350, thus, the description of thedetermining method of step S350 is omitted. When the operation statusdoes not correspond to the second pre-determined condition, errorinformation is sent (step S331) and the reformer is de-activated (stepS332). When the operation status corresponds to the secondpre-determined condition, the reformer is activated (step S340). In oneembodiment, the elements in the reformer are sequentially activated. Theelements may comprise a methanol pump, an electromagnetic valve, a heatconverter, an ignition, a burner and so forth.

Then, it is determined again whether the operation status corresponds tothe second pre-determined condition (step S350). When the operationstatus does not correspond to the second pre-determined condition, errorinformation is sent (step S331) and the reformer is de-activated (stepS332). When the operation status corresponds to the secondpre-determined condition, it is determined whether the reformercorresponds to a turning off condition (step S360). When the reformercorresponds to the turning off condition, the reformer is de-activated(step S370).

FIG. 4 is a schematic diagram of an exemplary embodiment of a standbymode. First, it is determined whether the city energy corresponds to afirst pre-determined condition (step S410). When the city energy doesnot correspond to the first pre-determined condition, it represents thatthe city energy is unstable. Thus, a pre-turning on mode is entered(step S411). When the city energy corresponds to the firstpre-determined condition, it represents that the city energy is stable,thus, the internal temperature of the power supplying system iscontrolled (step S420). In one embodiment, in step S420 is to controlthe temperature of a cooling water of the fuel cell unit 240.

Then, it is determined whether a recombination status of the reformercorresponds to a first pre-determined status (step S430). In oneembodiment, in step S430 is to determine at least one of an operation ofa fan, a hydrogen concentration status and a temperature status. Forexample, when an operation status of a hydrogen concentration protectiondevice of the recombination unit is abnormal, the hydrogen concentrationin the recombination unit may be too high. Thus, the operation of thehydrogen concentration protection device is detected to determinewhether the recombination status of the reformer corresponds to thefirst pre-determined status.

When the recombination status does not correspond to the firstpre-determined status, error information is sent and the reformer isde-activated (step S431). In another embodiment, no error information issent and only the reformer is de-activated. When the recombinationstatus corresponds to the first pre-determined status, the recombinationconfirmed action shown in FIG. 3 is executed.

FIG. 5 is a schematic diagram of an exemplary embodiment of apre-turning on mode. During the pre-turning on mode, the fuel cell unitof the power supplying system is activated (step S510). In oneembodiment, in step S510, the detectors 244˜246 of the fuel cell unit240, the hydrogen concentration protection device 247 and the coolingwater supply device 241 are activated.

Then, it is determined whether the operation statuses of therecombination unit and the fuel cell unit are normal (step S520). In oneembodiment, in step S520, whether the recombination status of therecombination unit corresponds to the first pre-determined status and afuel status of the fuel cell unit corresponds to a second pre-determinedstatus, are determined. When the recombination status does notcorrespond to the first pre-determined status or the fuel status doesnot correspond to the second pre-determined status, the reformer and thefuel cell unit are de-activated (step S521). In one embodiment, in stepS521, the detectors 244˜246 of the fuel cell unit 240, the hydrogenconcentration protection device 247 and the cooling water supply device241 are de-activated. In other embodiments, when the reformer isde-activated, error information is sent.

When the recombination status corresponds to the first pre-determinedstatus and the fuel status corresponds to the second pre-determinedstatus, it is determined whether a power of a power storage device ofthe power supplying system corresponds to a first pre-determined power(step S530). When the power of a power storage device does notcorrespond to the first pre-determined power, a turning on mode isentered into (step S531) to make the power storage device have enoughpower. When the power of a power storage device corresponds to the firstpre-determined power, it is determined whether the city energycorresponds to the first pre-determined condition (step S540).

When the city energy does not correspond to the first pre-determinedcondition, the recombination confirmed action shown in FIG. 3 isexecuted. When the city energy corresponds to the first pre-determinedcondition, it is determined whether the duration time corresponding tothe first pre-determined condition has reached a pre-determined time(step S550). When the duration time has reached the pre-determined time,it represents that the city energy is stable. Thus, the fuel cell unitis de-activated and the standby mode is entered (step S560). When theduration time has not reached the pre-determined time, the recombinationconfirmed action is executed.

FIG. 6A is a schematic diagram of an exemplary embodiment of a turningon mode. During the turning on mode, it is determined whether the amountof the hydrogen component disposed in the hydrogen storage devicecorresponds to the hydrogen condition (step S610). In one embodiment,the hydrogen condition described in step S610 is a minimum hydrogenamount, such as a minimum amount required by the fuel cell unit.

Refer to FIG. 6B, when the amount of the hydrogen component disposed inthe hydrogen storage device does not correspond to the hydrogencondition, the reformer is de-activated (step S611) and a turning offmode is entered (step S612). Refer to FIG. 6A, when the amount of thehydrogen component disposed in the hydrogen storage device correspondsto the hydrogen condition, a protection device of the power supplyingsystem is activated (step S620). In one embodiment, the protectiondevice is a relay connected to a power source, an over-currentprotection element, or a discharging resistor.

Then, it is determined whether a water status of the fuel statuscorresponds to a first pre-determined value of the second pre-determinedstatus (step S630). In one embodiment, in step S630, whether a maincooling water loop of the cooling water supply device of the fuel cellunit is normal is determined.

When the water status does not correspond to the first pre-determinedvalue, it represents that the cooling water supply device of the fuelcell unit is abnormal. Thus, the reformer is de-activated (step S611)and the turning off mode is entered (step S612). When the water statuscorresponds to the first pre-determined value, it represents the coolingwater supply device of the fuel cell unit is normal. Thus, it isdetermined whether the power generated by the fuel cell unit correspondsto a second pre-determined power (step S640).

When the power generated by the fuel cell unit does not correspond tothe second pre-determined power, the protection device is activated(step S641) and a hydrogen supply device of the fuel cell unit isactivated (step S642). When the power generated by the fuel cell unitcorresponds to the second pre-determined power, step S642 is executed.

Refer to FIG. 6B, it is determined whether a hydrogen status of the fuelstatus corresponds to a second pre-determined value of the secondpre-determined status (step S650). When the hydrogen status does notcorrespond to the second pre-determined value, the reformer isde-activated (step S611) and the turning off mode is entered (stepS612). When the hydrogen status corresponds to the second pre-determinedvalue, it is determined whether the power generated by the fuel cellunit corresponds to the second pre-determined power (step S660).

When the power generated by the fuel cell unit does not correspond tothe second pre-determined power, the protection device is againactivated (step S661) and the air supply device of the fuel cell unit isactivated (step S662). When the power generated by the fuel cell unitcorresponds to the second pre-determined power, step S662 is executed.

Next, it is determined whether an air status of the fuel statuscorresponds to a third pre-determined value of the second pre-determinedstatus (step S670). When the air status does not correspond to the thirdpre-determined value, the reformer is de-activated (step S611) and theturning off mode is entered (step S612). When the air status correspondsto the third pre-determined value, it is determined whether the powergenerated by the fuel cell unit corresponds to a third pre-determinedpower (step S680).

When the power generated by the fuel cell unit does not correspond tothe third pre-determined power, the reformer is de-activated (step S611)and the turning off mode is entered (step S612). When the powergenerated by the fuel cell unit corresponds to the third pre-determinedpower, the cooling water supply device of the fuel cell unit is adjusted(step S681) and the operation mode is entered (step S690). In oneembodiment, in step S681, a sub-cooling water loop of the cooling watersupply device is adjusted.

FIG. 7A is a schematic diagram of an exemplary embodiment of theoperation mode. During the operation mode, the fuel cell unit is coupledto the power transformation unit (step S710) and it is determinedwhether the fuel status corresponds to the second pre-determined status(step S720). In one embodiment, in step S720, the operation status of anair line of the fuel cell unit is determined. The air line transmits anair component. When the pressure of the air line is less than apre-determined pressure, it represents that the fuel status does notcorrespond to the second pre-determined status. Refer to FIG. 7B, thereformer is de-activated (step S721) and the turning off mode is entered(step S722).

Refer to FIG. 7A, when the pressure of the air line is larger than thepre-determined pressure, it represents that the fuel status correspondsto the second pre-determined status. Thus, the power generated by thefuel cell unit is adjusted according to the status of the load (stepS723) and it is determined whether an output current of the fuel cellunit is larger than a pre-determined current (step S730). When theoutput current of the fuel cell unit is larger than the pre-determinedcurrent, the protection device is de-activated (step S740) and controlseach supply device of the fuel cell unit to adjust the hydrogen, thecooling water and the air provided to the cell stack (step S750). Whenthe output current of the fuel cell unit is not larger than thepre-determined current, step S750 is executed.

The invention does not limit how each supply device is controlled instep S750. FIG. 7C is a schematic diagram of an exemplary embodiment ofcontrolling each supply device. In this embodiment, the cooling watersupply device of the fuel cell unit 240 is controlled according to theload (step S751) to adjust the cooling water received by the cell stack.Then, it is determined whether a water status of the fuel cell unitcorresponds to a first pre-determined value (step S752). The firstpre-determined value in step S752 is the same as the firstpre-determined value in step S630.

When the water status of the fuel cell unit does not correspond to thefirst pre-determined value, step S721 is executed. When the water statusof the fuel cell unit corresponds to the first pre-determined value, thehydrogen supply device of the fuel cell unit 240 is controlled accordingto the load (step S753) to adjust the hydrogen received by the cellstack 249. Next, it is determined whether the hydrogen status of thefuel cell unit corresponds to a second pre-determined value (step S754).The second pre-determined value in step S754 is the same as the secondpre-determined value in step S650.

When the hydrogen status does not correspond to the secondpre-determined value, step S721 is executed. When the hydrogen statuscorresponds to the second pre-determined value, the air supply device ofthe fuel cell unit 240 is controlled according to the load (step S755)to adjust the air received by the cell stack 249. Then, it is determinedwhether the air status of the fuel cell unit corresponds to a thirdpre-determined value (step S756). The third pre-determined value in stepS756 is the same as the third pre-determined value in step S670.

When the air status of the fuel cell unit does not correspond to thethird pre-determined value, step S721 is executed. When the air statusof the fuel cell unit corresponds to the third pre-determined value,step S760 is executed.

The invention does not limit the sequence of executing steps S751, S753and S755. In this embodiment, the cooling water supply device, thehydrogen supply device and the air supply device are sequentiallyadjusted, but the disclosure is not limited thereto. In otherembodiments, the cooling water supply device, the hydrogen supply deviceand the air supply device are adjusted according to other sequences.

Refer to FIG. 7A, after executing step S750, it is determined whetherthe power generated by the fuel cell unit corresponds to the thirdpre-determined power (step S760) to confirm whether the power generatedby the fuel cell unit is normal. Refer to FIG. 7B, when the powergenerated by the fuel cell unit does not correspond to the thirdpre-determined power, the reformer is de-activated (step S721) and theturning off mode is entered (step S722). When the power generated by thefuel cell unit corresponds to the third pre-determined power, it isdetermined whether the city energy corresponds to the firstpre-determined condition (step S770).

Refer to FIG. 7B, when the city energy does not correspond to the firstpre-determined condition, the recombination confirmed action shown inFIG. 3 is executed. When the city energy corresponds to the firstpre-determined condition, it is determined whether the duration timecorresponding to the first pre-determined condition has reached thepre-determined time (step S780). When the duration time has not reachedthe pre-determined time, the recombination confirmed action shown inFIG. 3 is executed. When the duration time has reached thepre-determined time, it is determined whether the power of the powerstorage device corresponds to the first pre-determined power (stepS790). When the power of the power storage device does not correspond tothe first pre-determined power, the recombination confirmed action shownin FIG. 3 is executed. When the power of the power storage devicecorresponds to the first pre-determined power, the turning off mode isentered (step S722).

FIGS. 8A and 8B are schematic diagrams of an exemplary embodiment of aturning off mode. During the turning off mode, the protection device isactivated (step S810), each supply device of the fuel cell unit isde-activated (step S811) and the standby mode is entered (step S812).The invention does not limit the sequence of de-activating each supplydevice. In this embodiment, the air supply device, the hydrogen supplydevice and the cooling water supply device are sequentiallyde-activated. In other embodiments, each supply device is de-activatedaccording to other sequences.

In this embodiment, the air supply device is first de-activated (stepS820) and it is determined whether the air supply device has beende-activated (step S830). When the air supply device has not beende-activated, error information is sent (step S831) and then thehydrogen supply device has been de-activated (step S840). When the airsupply device has been de-activated, it is determined whether the powergenerated by the fuel cell unit is less than a pre-determined power(step S832).

When the power generated by the fuel cell unit is less than thepre-determined power, the hydrogen supply device has been de-activated(step S840). Then, it is determined whether the hydrogen supply devicehas been de-activated (step S850). When the hydrogen supply device hasnot been de-activated, error information is sent (step S851) and thenthe cooling water supply device is de-activated (step S852). In oneembodiment, in step S852, a cooling water loop is turned off. When thehydrogen supply device has been de-activated, the cooling water supplydevice is de-activated (step S852).

Refer to FIG. 8B, it is determined whether the cooling water supplydevice has been de-activated (step S860). When the cooling water supplydevice has not been de-activated, error information is sent (step S861)and then each detector and the fan of the fuel cell unit arede-activated (step S862). When the cooling water supply device has beende-activated, each detector and the fan of the fuel cell unit arede-activated (step S862).

Next, it is determined whether the error information has been sent (stepS870). When the error information has been sent, the error informationis displayed and the backup power V_(SUB) is stopped (step S871). Asshown in FIG. 2A, when the city energy is unstable, a backup power isprovided to the load. However, when the error information occurs, itrepresents that the backup power is abnormal. Thus, the backup power isstopped from being provided to the load. In other words, the operationsof units 230˜260 are stopped until an abnormal status is eliminated. Inone embodiment, after eliminating the abnormal status, a tester cuts offthe power of the units 230˜260 and then provides the power to the units230˜260. When the error information has not been sent, the standby modeis entered (step S812).

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

While the invention has been described by way of example and in terms ofthe preferred embodiments, it is to be understood that the invention isnot limited to the disclosed embodiments. To the contrary, it isintended to cover various modifications and similar arrangements (aswould be apparent to those skilled in the art). Therefore, the scope ofthe appended claims should be accorded the broadest interpretation so asto encompass all such modifications and similar arrangements.

What is claimed is:
 1. A power controlling method for a power supplyingsystem coupled to a load, comprising: detecting an energy; determiningwhether the energy corresponds to a first pre-determined condition;transforming the energy to generate a main power to the load when theenergy corresponds to the first pre-determined condition; activating afuel cell unit to provide a backup power to the load when the energydoes not correspond to the first pre-determined condition; and executinga recombination confirmed action in a standby mode, a pre-turning onmode and an operation mode, wherein the recombination confirmed actioncomprises: determining whether a reformer of the power supplying systemis activated; determining whether an operation status of the reformercorresponds to a second pre-determined condition when the reformer isactivated, wherein when the operation status does not correspond to thesecond pre-determined condition, the reformer is de-activated, and whenthe operation status corresponds to the second pre-determined condition,it is determined whether the reformer corresponds to a turning offcondition, and when the reformer corresponds to the turning offcondition, the reformer is de-activated; and determining whether thereformer needs to be activated when the reformer is not activated,wherein when the reformer does not need to be activated, a temperatureof the reformer is controlled and a situation is avoided where thereformer is oxidized, and when the reformer needs to be activated, it isdetermined whether the operation status corresponds to the secondpre-determined condition, and when the operation status does notcorrespond to the second pre-determined condition, the reformer isde-activated, and when the operation status corresponds to the secondpre-determined condition, the reformer is turned on and it is againdetermined whether the operation status corresponds to the secondpre-determined condition, and when the operation status does notcorrespond to the second pre-determined condition, the reformer isde-activated, and when the operation status still corresponds to thesecond pre-determined condition, it is determined whether the operationstatus corresponds to the second pre-determined condition, and when thereformer corresponds to the turning off condition, the reformer isde-activated.
 2. The power controlling method as claimed in claim 1,wherein the step of determining whether the reformer corresponds to theturning off condition is to determine whether an amount of a hydrogencomponent disposed in a hydrogen storage device of the reformercorresponds to a hydrogen condition, wherein when the amount of thehydrogen component disposed in the hydrogen storage device of thereformer corresponds to the hydrogen condition, it represents that thereformer corresponds to the turning off condition, and when the amountof the hydrogen component disposed in the hydrogen storage device of thereformer does not correspond to the hydrogen condition, it representsthat the reformer does not correspond to the turning off condition,wherein the step of determining whether the reformer needs to beactivated is to determine whether the amount of the hydrogen componentdisposed in the hydrogen storage device of the reformer corresponds tothe hydrogen condition, and when the amount of the hydrogen componentdisposed in the hydrogen storage device of the reformer corresponds tothe hydrogen condition, it represents that the reformer does not need tobe activated, and when the amount of the hydrogen component disposed inthe hydrogen storage device of the reformer does not correspond to thehydrogen condition, it represents that the reformer needs to beactivated, wherein the step of determining whether the operation statuscorresponds to the second pre-determined condition is to determine atleast one of the temperature of the reformer, an amount of methanolcomponent disposed in a methanol tub of the reformer, and the amount ofhydrogen component disposed in the hydrogen tub of the reformer.
 3. Thepower controlling method as claimed in claim 2, during the standby mode,further comprising: determining whether the energy corresponds to thefirst pre-determined condition; entering the pre-turning on mode, whenthe energy does not correspond to the first pre-determined condition;controlling an internal temperature of the power supplying system anddetermining whether a recombination status of the reformer correspondsto a first pre-determined status when the energy corresponds to thefirst pre-determined condition; de-activating the reformer when therecombination status does not correspond to the first pre-determinedstatus; and executing the recombination confirmed action when therecombination status corresponds to the first pre-determined status,wherein the recombination status is at least one of an operation statusof a fan, a hydrogen concentration status and a temperature status. 4.The power controlling method as claimed in claim 3, wherein the step ofdetermining whether the recombination status corresponds to the firstpre-determined status is to determine whether an operation of a hydrogenconcentration protection device of the reformer is normal.
 5. The powercontrolling method as claimed in claim 3, during the pre-turning onmode, further comprising: activating a fuel cell unit of the powersupplying system and determining whether the recombination statuscorresponds to the first pre-determined status and a fuel status of thefuel cell unit corresponds to a second pre-determined status,de-activating the reformer and the fuel cell unit when the recombinationstatus does not correspond to the first pre-determined status or thefuel status of the fuel cell unit does not correspond to the secondpre-determined status, determining whether a power of a power storagedevice of the power supplying system corresponds to a firstpre-determined power when the recombination status corresponds to thefirst pre-determined status and the fuel status of the fuel cell unitcorresponds to the second pre-determined status; entering a turning onmode when the power of the power storage device does not correspond tothe first pre-determined power; determining whether the energycorresponds to the first pre-determined condition when power of thepower storage device corresponds to the first pre-determined power;executing the recombination confirmed action when the energy does notcorrespond to the first pre-determined condition; and de-activating thefuel cell unit and entering the standby mode when the energy correspondsto the first pre-determined condition.
 6. The power controlling methodas claimed in claim 5, during the turning on mode, further comprising:determining whether the amount of the hydrogen component disposed in thehydrogen storage device corresponds to the hydrogen condition;de-activating the reformer and entering a turning off mode when theamount of the hydrogen component disposed in the hydrogen storage devicedoes not correspond to the hydrogen condition; activating a protectiondevice of the power supplying system and determining whether a waterstatus of the fuel status corresponds to a first pre-determined value ofthe second pre-determined status when the amount of the hydrogencomponent disposed in the hydrogen storage device corresponds to thehydrogen condition; de-activating the reformer and entering the turningoff mode when the water status does not correspond to the firstpre-determined value; determining whether a power generated by the fuelcell unit is less than a second pre-determined power when the waterstatus corresponds to the first pre-determined value; activating theprotection device again and adjusting a hydrogen supply device of thefuel cell unit when the power generated by the fuel cell unit is notless than the second pre-determined power; adjusting the hydrogen supplydevice and determining whether a hydrogen status of the fuel statuscorresponds to a second pre-determined value of the secondpre-determined status when the power generated by the fuel cell unit isless than the second pre-determined power; de-activating the reformerand entering the turning off mode when the hydrogen status does notcorrespond to the second pre-determined value; determining whether thepower generated by the fuel cell unit is less than the secondpre-determined power when the hydrogen status corresponds to the secondpre-determined value; activating the protection device again andadjusting an air supply device of the fuel cell unit when the powergenerated by the fuel cell unit is not less than the secondpre-determined power; adjusting the air supply device and determiningwhether an air status of the fuel status corresponds to a thirdpre-determined value of the second pre-determined status when the powergenerated by the fuel cell unit is less than the second pre-determinedpower; de-activating the reformer and entering the turning off mode whenthe air status does not correspond to the third pre-determined value;determining whether the power generated by the fuel cell unitcorresponds to a third pre-determined power when the air statuscorresponds to the third pre-determined value; de-activating thereformer and entering the turning off mode when the power generated bythe fuel cell unit does not correspond to the third pre-determinedpower; and adjusting a cooling water supply device of the fuel cell unitand entering the operation mode when the power generated by the fuelcell unit corresponds to the third pre-determined power.
 7. The powercontrolling method as claimed in claim 6, during the operation mode,further comprising: connecting the fuel cell unit to a powertransformation unit and determining whether the fuel status correspondsto the second pre-determined status; de-activating the reformer andentering the turning off mode when the fuel status does not correspondto the second pre-determined status; and adjusting the power generatedby the fuel cell unit according to the load when fuel status correspondsto the second pre-determined status; determining whether an outputcurrent of the fuel cell unit is larger than a pre-determined current;de-activating the protection device, and controlling the hydrogen supplydevice, the air supply device and the cooling water supply deviceaccording to the load, and determining whether the fuel statuscorresponds to the second pre-determined status when the output currentof the fuel cell unit is larger than the pre-determined current;controlling the hydrogen supply device, the air supply device and thecooling water supply device according to the load and determiningwhether the fuel status corresponds to the second pre-determined statuswhen the output current of the fuel cell unit is not larger than thepre-determined current; de-activating the reformer and entering theturning off mode when the fuel status does not correspond to the secondpre-determined status; determining whether the power generated by thefuel cell unit corresponds to the third pre-determined power when thefuel status corresponds to the second pre-determined status;de-activating the reformer and entering the turning off mode when thepower generated by the fuel cell unit does not correspond to the thirdpre-determined power; determining whether the power generated by thefuel cell unit corresponds to the first pre-determined power when thepower generated by the fuel cell unit corresponds to the thirdpre-determined power, wherein when the power generated by the fuel cellunit corresponds to the first pre-determined power, the turning off modeis entered, determining whether the energy corresponds to the firstpre-determined condition and the power of the power storage devicecorresponds to the first pre-determined power; and executing therecombination confirmed action when the energy does not correspond tothe first pre-determined condition or the power of the power storagedevice does not correspond to the first pre-determined power.
 8. Thepower controlling method as claimed in claim 7, wherein the step ofdetermining whether the fuel status corresponds to the secondpre-determined status is to determine whether the water statuscorresponds to the first pre-determined value, the hydrogen statuscorresponds to the second pre-determined value, and the air statuscorresponds to the third pre-determined value, wherein the reformer isde-activated and the turning off mode is entered when the water statusdoes not correspond to the first pre-determined value, the hydrogenstatus does not correspond to the second pre-determined value, or theair status does not correspond to the third pre-determined value.
 9. Thepower controlling method as claimed in claim 8, during the turning offmode, further comprising: activating the protection device;de-activating the hydrogen supply device, the air supply device and thewater supply device of the fuel cell unit; and entering the standbymode.